Add changelog

diff --git a/doc/build/changelog/unreleased_20/12117.rst b/doc/build/changelog/unreleased_20/12117.rst
new file mode 100644 (file)
index 0000000..a6d1ffc
--- /dev/null
+++ b/doc/build/changelog/unreleased_20/12117.rst
@@ -0,0 +1,6 @@
+.. change::
+    :tags: bug, dml, mariadb, mysql
+    :tickets: 12117
+
+    Fixed a bug where the :class:`MySQLCompiler` would not properly compile statements
+    that include the ``on_duplicate_key_update`` :class:`InstrumentedAttribute` object.